Abstract: A raku kiln has a fire ring with a cylindrical sidewall and bottom made of refractory material with a kiln shelf supported a few inches above the bottom to enclose a space that is superheated by burners. A firing-chamber rests on the fire ring and is lifted by a two aligned pulleys on top of a pole which rotates to move the chamber out of the way. A vertical pole mates with tubes on the chamber for vertical guidance during raising and lowering of the chamber. Flanges on the lower end of the chamber allow adding an extension chamber.

Abstract: The method according to the invention for operating a PFR lime kiln having at least two shafts, which each have a preheating zone, a combustion zone and a cooling zone, and an overflow channel which connects the two shafts, substantially comprises the following method steps: the two shafts are operated alternately as a combustion shaft and exhaust gas shaft, combustion air and fuel are supplied to the combustion shaft, a corresponding flame length being formed, and the hot gases which are produced in the combustion shaft reach the exhaust gas shaft via the overflow channel, at least one parameter of the hot gases which is characteristic of the formation of the flame length being established by means of direct or indirect measurement in the region of the overflow channel and the ratio of fuel to combustion air being adjusted in accordance with this parameter in order to adjust a predetermined flame length.

Abstract: A rotary charging device for a shaft furnace commonly comprises a rotary distribution configured to distribute charge material on a charging surface in the shaft furnace. A rotatable structure supports the rotary distribution means and a stationary support rotatably supports the rotatable structure. According to the invention, the charging device is equipped with an inductive coupling device including a stationary inductor fixed to the stationary support and a rotary inductor fixed to the rotatable structure. The stationary inductor and the rotary inductor are separated by a radial gap and configured as rotary transformer for achieving contact-less electric energy transfer from the stationary support to the rotatable structure by means of magnetic coupling through the radial gap for powering an electric load arranged on the rotatable structure and connected to said rotary inductor.

Abstract: The invention relates to a shaft furnace (10) and a method for heat treating carbonaceous molded parts, particularly anodes (17), having an arrangement of the molded parts in at least one molded part column (11 to 15) disposed between tempering shaft devices (19, 20, 21) comprising a plurality of molded part rows (16) disposed above each other in a conveyor shaft, the rows being moved past temperature fields of the tempering shaft devices (19, 20, 22) and passing through a heating zone (25), a firing zone (27) having a burner device (28), and a cooling zone (26), wherein thermally insulating intermediate layers are disposed both between the temperature fields of the tempering shaft devices (19, 20, 22) and between the molded part rows of the molded part columns.

Abstract: A method for removing sulfur containing dust particles from particulate material exiting a material preheater in which the particulate material is heated by kiln off gases may include a number of steps. Off gases from the kiln are directed through a gas conduit to the preheater to preheat particulate material traveling through the preheater in a direction countercurrent to the direction of off gas flow through the preheater. Material exiting the preheater is directed to a material bypass conduit that is separated from the gas conduit and is flow connected to a material inlet to the kiln. A stripping gas is directed through the conduit to entrain dust particles in the preheated material and to carry said dust particles away from the preheated material.

Abstract: The invention relates to a feeding device for a belt-type sintering machine, with a feeding container for receiving the material to be sintered, with a conveying device for filling the feeding container with material to be sintered, with a feeding drum and a drum chute for feeding the material to be sintered onto the sintering belt. The feeding container has two discharge openings, one of which is connected to a feeding drum and one of which is connected to a feeding chute.

Abstract: The present invention relates to a vertical furnace for fabricating an artificially lightweight fine-aggregates in that the aggregate,; can he fired in the vertical furnace in a floating state, so that the contacting time between the aggregates can he minimized, thereby preventing the adhesion between the aggregates and manufacturing the artificially lightweight fine-aggregates as an insulating concrete for building material, sound-absorbing materials, and lagging material.

Abstract: A fuel delivering terminal (1) is disclosed adapted to be connected to a delivery end of a combustion lance (3) of lime regenerating ovens, wherein D is the external diameter of the terminal (1) and is greater that the internal diameter d of the delivery end of the combustion lance (3); a combustion lance equipped with the terminal (1) and a system and a process for controlling the fuel supply flow through such lances are also disclosed.

Abstract: A method for burning lumps of material, in particular limestone, is carried out in a regeneration shaft kiln (3) with at least two kiln shafts (1, 2) interconnected by an overflow line (19) and in which the material to be burned passes through an upper pre-heating zone (8), a central combustion zone (18) and a lower cooling zone (14). Combustion gas with a low calorific value of less than 7.5 megajoules (MJ) per m3 is periodically and alternately supplied to each of the shafts (1, 2) through burner lances (9, 25) after being pre-heated by heat exchange with process gas of the combustion process. The combustion gas is pre-heated in a heat exchanger (21) and/or by means of a surface of the burner lances (9, 25) which extend through the pre-heating zone (8), said surface being enlarged to enhance heat exchange.

Abstract: A device for distributing bulk materials includes a suspension rotor is mounted in a support frame which is capable of rotating about a substantially vertical axis of rotation. A chute is suspended to the suspension rotor and is tiltable about a substantially horizontal tilt axis. A first motor is capable of rotating the suspension rotor about its axis of rotation in a first direction, and a tilt controlling motor mounted in the support frame is capable of rotating about a substantially vertical axis of rotation. A tilting mechanism is also connected between the chute and the tilt controlling rotor, while a first braking device exerts a braking moment on the tilt controlling motor. A first control device controls the angle of inclination of the chute by controlled braking of the tilt controlling rotor.

Abstract: A blast furnace head (11) including a material loading device comprising rotary chute (14) driven in rotation about a first, vertical axis of rotation (16), and a loading chute (15) at the outlet of same, driven in rotation about a second, vertical axis of rotation (17) laterally offset relative to the first axis of rotation (16). The gears (20, 21) assigned to both of the chutes (14, 15) are arranged within a sealing chamber (22). Within this sealing chamber (22), a means (28) is arranged for supplying integrated measuring devices (29 or 30), lubrication points or similar maintenance recipients, with these supply means (28) being drivable by one of the gears (20, 21) assigned to the two chutes, in particular by the gear (20) assigned to the rotary chute (14).

Abstract: An apparatus for preheating particulate material in which the particulate material is transferred from one or more upper storage bins to a circular lower chamber that has an outer, essentially annular, portion which serves as a gas flow passage. The particulate material is directed from the feed bin or bins into a plurality of essentially vertical cylindrical feed cassettes via intermediate feed ducts. The lower chamber has a flat roof which is in contact with the bottom portion of the vertical feed cassettes. The vertical feed cassettes are approximately evenly spaced on top of the outer perimeter of the flat roof. The particulate material is preheated in the annular flow passage by hot kiln gases flowing in countercurrent heat exchange relationship with the particulate material.

Abstract: A loading device for a shaft furnace comprises a chute supported by a suspension rotor (28) in a fixed housing. The rotor (28) is fitted with a cooling circuit, supplied with liquid coolant via a rotating annular joint (44). The latter comprises a fixed ring (60) and a rotating ring (62), and is fitted in an annular leak collecting tank (46) formed by the suspension rotor (28). Fixed ring (60) is supported by the housing (12). Rotating ring (62) is supported entirely by fixed ring (60) via a bearing (64). Selective coupling means (65, 66) connect the rotating ring (62) to the suspension rotor (28) in such a way as to transmit a rotary moment of rotor (28) to rotating ring (62) selectively, while at the same time preventing other forces from rotor (28) being transmitted to rotating ring (62).

Abstract: A method for burning lumpy combustion material, in particular limestone, dolomite and magnesite, in a regenerative shaft furnace comprising at least two shafts (1, 2) comprised of a preheating zone (A) as well as a combustion zone (B). The shafts are connected below a cooling zone (C) by a transfer channel (3). The combustion air is charged at the head of one shaft (1), heated by hot combustion material as it flows through the preheating zone (A), and brought into contact with fuel before it enters the combustion zone (B). The combustion zone (B) is flowed through by combustion gas produced in the combustion of the fuel. Cooling air is admitted at the lower end of the shaft (1) and, as it flows through the cooling zone (C), heated by hot combustion material exiting from the combustion zone.

Abstract: In a method for burning carbonate-containing material the latter moves as a result of gravity in counter-current to the cooling and combustion air through a shaft kiln. The fuel supply takes place by means of burning lances introduced into the granular burning material at right angles to the shaft wall. On limiting the grain size and the residence time as a result of this type of fuel supply it is possible to achieve high burning temperatures even suitable for hard burning without there being any sintering together of the granular burning material.

Abstract: A method of reclaiming foundry sand by (a) providing a treatment tower having a plurality of heat conductive tubes extending across the interior of the treatment tower, the tubes being arranged in rows and staggered with respect to tubes in adjacent rows to create close spacing therebetween sufficient to permit the sand to flow continuously and non-turbulently along the contours of the exterior under the influence of gravity before dropping to the next adjacent tube to thereby again flow continuously and non-turbulently in successive sequence downwardly of the tower; (b) quiescently heating the interior tower space and tubes to a temperature in excess of 1300.degree. F.

Abstract: A regenerative shaft kiln having at least two vertical shafts and a plurality of lances for introducing fuel into the kiln, with one or more sensor provided proximate a plurality of the lances, each of the sensors producing a first output signal having a magnitude and corresponding to a physical parameter of the kiln adjacent the sensor. Observation of the operating conditions of individual lances enables adjustments to the fuel feed via individual lances to avoid equipment damage and to improve kiln performance.

Abstract: This invention relates to a sealing device useful for attachment to a process equipment such as vertical shaft kiln (VSK) for providing air-seal self-controlled discharge of product from the said equipment, which comprises a chamber (1) having at its top end an inlet (3) with flange (2) for fitting to the discharge chute of a process equipment and a discharge outlet (16) at its bottom end, the said chamber being provided with a partition wall (4) having an inlet gate (5) & a discharge gate (6) hinged to its top & bottom respectively, the free ends of the hinged gates being such as to sit on means (7) and (8) to provide air seal, means (9,10,11,12,13,14,15,17,18,19,20& SOL) being provided for simultaneous operation of the inlet & discharge gates, the said means [9(a) & (b) and SOL] being connected to a control circuit for actuating the movement of the gates, the discharge outlet being fitted onto a volumetric discharge unit (21) provided with means (22) for measuring the quantity of product discharge.

Abstract: An improved hearth section for a shaft furnace may comprise a plurality of splines mounted to the side wall of the hearth section in spaced-apart circumferential positions so that each of the splines extends radially inward from the side-wall and into the interior of the hearth section. The floor of the hearth section may include a plurality of stand-offs positioned in generally spaced-apart relation and that extend upward from the floor and into the interior of the hearth section.

Abstract: This invention relates to a a vertical shaft kiln (VSK) useful for manufacturing cement and other allied products, which comprises a rotary nodule feeder for feeding the raw materials, fitted above the kiln bed for uniform distribution of nodules of the raw materials, an air blower being placed at the base of the kiln for feeding air through a duct to a common air header having a plurality of outlet air ducts, the air duct being connected to an air cone placed inside an armoured shell of the VSK, the said air cone being provided with a grate assembly having a plurality of peripheral air slots, the air duct being connected to an air box placed above the said armoured shell, the said air box having perforations on the inside vertical wall, the air duct being connected to an air header having air entry nozzles placed in such a manner so as to supply air just below the sintering zone of the VSK, the air duct being connected to the chimney of the VSK, the said chimney being provided with a butterfly valve below th

Abstract: A shaft furnace for reduction of oxides includes a shaft member having an oxide inlet and defining a pre-heating and pre-reducing zone downstream of the oxide inlet, a reducing zone downstream of the pre-heating and pre-reducing zone a transition zone downstream of the reducing zone, and a discharge zone downstream of the transition zone; and a gas reforming zone associated with the shaft member for reforming a methane-containing gas into a reformed gas and for introducing the reformed gas into the reducing zone whereby oxides in the reducing zone are reduced by the reformed gas.

Abstract: Disclosed is a method and an apparatus for the heat treatment of lime sludge (CaCO.sub.3) to form burnt lime (CaO). In the method of the present invention lime sludge is dried in a gas dryer means, to produce a dried lime sludge. The dried lime sludge is separated from the gases and thereafter is first fed to a compacting means wherein it is compacted into a plurality of substantially uniform bodies which are thereafter fed to a shaft kiln in which the compacted dried lime sludge is converted to active burnt lime.

Abstract: A control measuring and supply apparatus and method for receiving a substantially, continuous flow of fluent material from a source of supply; the assembly having a bottom-sealed diverter plate, optionally positionable to direct the fluent material, by gravity, to either one or the other of a pair of adjacent, parallel supply chambers, each of the supply chambers having lower, sealed valve plates which can be optionally opened or closed, a and visa versa, one of the supply chambers being filled with the fluent material while the other is simultaneously emptied, and power operated control motors for controlling the operation of the diverter and valve plates; the diverter plate and valve plates cooperating with seals disposed out of the path-of-movement of the fluent material.

Abstract: A vertical bright-annealing furnace 1 for metal strips includes a muffle-type heating station 12, a refractory-type heating station 13. The refractory-type heating station 13 includes a shell 24 lined with a heat-insulating material 26 and a second heater 27. These two stations 12 and 13 are connected to one another by a flexible connecting unit 14 which is extensible in the longitudinal direction of the heating zone. A metal strip S conveyed in the furnace 1 is heated in the muffle-type heating station 12 and subsequently heated in the refractory-type heating station 13 up to a predetermined temperature, for example, about 1,100.degree. C. According to this constitution, a large-sized vertical annealing furnace may be constructed. Also, the period of durability of the muffle may be extended, the running expenses may be decreased, and metal strip having good brightness may be produced.

Abstract: A circulating fluidized bed thermal reactor such as a boiler or gasifier, having the riser divided into a sequence of stages by a plurality of restrictions which create multiple beds dynamically suspended. Circulation occurs below transport velocity, solids distribution is substantially uniform, average bed density can be varied from near-zero to very high values, solids mobility is unrestricted, temperature is uniform. Gases follow multistage CSTR flow regime, specially suited for fuels which break down into volatiles upon heating, such as biomass, hazardous wastes and most fuels other than coal.

Abstract: A method and a combustion furnace are provided by means of which waste which is predominantly of organic nature can be burnt effectively and uniformly. The combustion furnace comprises two bottlenecks, one above the other, constituted by rocking grates. The upper rocking grate essentially serves to subject the solids to pre-combustion, namely to drying, degasifying, and partial gasifying, and to supply the material uniformly in doses to the fire bed which is located on the lower grate and in which complete gasification takes place. Rotational movements of both grates provide for uniform passage of the material through the shaft without the risk of burn-through occurring along the edges so that the entire combustion process becomes highly uniform.

Abstract: A method and apparatus for thermally reclaiming used foundry sand is disclosed. The apparatus includes a vertically disposed furnace having a combustion chamber therein. A sand dispersion system supported within the combustion chamber disperses the free falling sand particles to expose the particles to a combustion supporting furnace environment. Disposed immediately below the furnace is a sand retention chamber in which the sand is accumulated. Heated air is introduced into the retention chamber to maintain the combustion supporting environment. Residual coatings remaining on the sand particles are thermally removed in the retention chamber.

Abstract: An improved method preheating cullet and glass batch together for use as feedstock for a glass furnace. The method uses a preheater including a separator and a heat exchanger. The heat exchanger is a direct contact raining bed in which large particles in the feedstock are heated by hot gases as the particles flow down by gravity and fine particles become entrained with the hot gas flow. The separator removes the fine particles entrained in the hot gases and remixes preheated the fine particles with the preheated cullet. Preheater systems are described in which the hot gasses are provided by the glass furnace exhaust, by a separately fired heater, by a separately fired heater combined with the glass furnace exhaust and by a separately fired heater with exhaust gas recirculation.

Abstract: A suspension shaft furnace and process for producing clinkers from discrete pellets of cement-forming batch materials, the furnace having a top vertical shaft section comprising a pellet-feeding and preheating zone, an intermediate fluidized bed section containing fuel inlet conduits for clinkering of the pellets in a fluidized bed, an air-permeable clinker-impermeable support for supporting the pellets as a fluidized bed, and a lower clinker-cooling section beneath the fluidized bed section. Clinker-discharge means permit the gravity flow of clinkers from the top of the fluidized bed down into a cooling zone in the cooling section. Air inlet means supply a combustion-supporting cooling gas up through the cooling zone, to cool the clinkers therein, and upstream through the fluidized bed section to support the combustion of fuel at the fuel inlet conduits.

Abstract: A method and apparatus for thermally reclaiming used foundry sand is disclosed. The apparatus includes a vertically disposed furnace having a combustion chamber therein. A sand dispersion system supported within the combustion chamber disperses the free falling sand particles to expose the particles to a combustion supporting furnace environment. Disposed immediately below the furnace is a sand retention chamber in which the sand is accumulated. Heated air is introduced into the retention chamber to maintain the combustion supporting environment. Residual coatings remaining on the sand particles are thermally removed in the retention chamber.

Abstract: Oven for dehydrating pulverulents, sand or granules, comprising an energy-saving dehydration device, adapted to gypsum burning. The device consists of an outer casing, an inner casing and flow cones disposed on said casings. A burner and a lock complete the device. Pressure within the oven is increased by the provision of a cover, a gypsum lock and a steam valve. The process takes place in dry or moist conditions, the latter being advantageous for the processing of insulating products or for gypsum amending the nature of plaster. Heat exchange enables the products to be processed at low temperatures. The central combustion chamber prevents loss by radiation. Application to gypsum burning, during which the device has demonstrated energy savings of 50% in comparison with traditional appliances.

Abstract: An apparatus for the thermal decomposition of a fluid toxic substance contained in a gas comprises a cylindrical main combustion chamber and a secondary combustion chamber arranged thereabove. An inlet opening leads into the main combustion chamber at an angle to introduce a stream of the gas containing the toxic substance into the main combustion chamber with an angular momentum, a burner is arranged to direct a flame into the main combustion chamber above the inlet opening for subjecting the gas containing the toxic substance to combustion, and an annular gas stream retaining device is arranged above the burner.

Abstract: The present invention relates to a novel process and to an installation for performing the process for calcining limestone for producing lime of different qualities, while being able to entirely or at least substantially do without conventional energy carriers such as coal, oil and natural gas. Instead waste energy carriers of different origins are used. According to the process the waste energy substances are firstly gasified in a suitable gasifier, which is constructed as a shaft reactor or fluidized bed reactor and at elevated temperature, the dust being then removed from the lean gas produced and subsequently passed into the combustion chambers of the gasification reactor where burning takes place. The pollutants in the waste energy carriers are destroyed or rendered harmless by the high temperature of approximately 1600.degree. C. in the gasification reactor. Dust and harmful components are then deposited in the coke filling or in the dust catchers.

Abstract: A preheater for cullet is disclosed, in which hot gas coming from a hot supply duct can be passed through the cullet while yielding heat to the latter and can be carried away through a hot gas exhaust duct. The cullet is guided between guiding walls forming a cullet shaft and permitting gas entry as well as gas exit. Means are provided for repeatedly moving at least one of the guiding walls (23, 24,25,26) laterally relative to another guiding wall (23-26) so as to change the spacing between them.

Abstract: An apparatus for gas/solids exchange has a column having a plurality of vertically spaced grates on which the granular solids can form beds to be traversed by the gas. Each grate is provided in a grate plane by a plurality of fixed grate bars interdigitated with movable grate bars forming a planar unit which can be displaced by a controller out of the grate plane to allow the granular solids on the respective grate to trickle downwardly uniformly over the cross section of the column onto the next lower grate.

Abstract: A vertical shaft kiln utilized in calcining limestone defines a series of processing zones including an upper preheating zone, a first calcining zone, a second calcining zone having a length twice that of the first calcining zone and a material cooling zone, Burners inject burnt gases intermediate the two calcining zones. Major heat transfer to the limestone is accomplished in the first calcining zone by directing a major portion of the burnt gases in counter-current to the material flow therethrough. Minor heat transfer is accomplished in the second calcining zone by directing a minor portion of the burnt gases therethrough in co-current relation with the material. Combustion air is provided through ducts in the material cooling zones and mixed with the minor portion of burnt gases externally of the shaft prior to injection into the burners.

Abstract: An improved annular shaft kiln for burning particulate material such as limestone which adds a bridge to the lower part of the annular material zone between the burning zone and the cooling zone. This bridge permits heated cooling gas and at least some of the spent cooling gas to be withdrawn from the annular zone and be supplied directly to the combustion chamber of the kiln.

Abstract: A method and apparatus is disclosed for burning and sintering alkaline materials such as limestone and dolomite in a shaft furnace wherein the alkaline material travels successively through a preheating, burning and cooling area. At the upper end of the cooling area the cooling air traversing the shaft from bottom to top is aspirated into a recuperator wherein fresh combustion air is preheated by the cooling air and then supplied to the burner which heats the burning area. Part of the aspirated cooling air may also be directed past the recuperator through a bypass conduit to heat a dryer which dries the materials to be processed by the shaft furnace.

Abstract: The invention utilizes fluid bed air heaters for burning coarse solid fuels which supply heated gases to annular shaft kilns or double inclined shaft kilns. The solid fuels are introduced into a fluidized bed of inert material, such as sand, alumina or ash, through means of an air lock and the hot gases of combustion pass through a cyclone separator to remove solid materials, which can be reintroduced into the fluidized bed. The hot gases are injected into the kilns to supply heat as needed for calcining or burning limestone or similar materials. Temperature control of the gas leaving the fluid bed air heater and reduced contamination of the burned materials are disclosed advantages of the present invention.

Abstract: A two stage material cooling apparatus for cooling hot particulate material such as cement clinker discharged from a furnace such as the rotary kiln. The first stage includes a direct heat exchanger such as a reciprocating grate type heat exchanger or an attached tube cooler and serves primarily as a heat recuperator. This cooler acts on the principle of direct heat exchange between cooling gas and the hot material whereby the material is cooled and the gas is heated and returned to the kiln as preheated secondary air for combustion. The second stage cooler is a shaft type cooler with gas permeable sides so that cooling gas passes through the material generally perpendicular to the flow of material. The gas which is supplied to the second cooler can come from recirculated cooling gas or from ambient. The gas discharged from the second cooler can be supplied directly to the gas inlet of the first cooler recirculated to its inlet after passing through an air to air heat exchanger.

Abstract: Packing for a column for treating solid particles by direct contact between an ascending gas current and solid particles flowing countercurrent by gravity within the packing. The packing has an ordered structure, consisting of superposition of at least two stacking elements (1,12), each comprising shaped elements (2, 9) arranged parallel between themselves and with regular spacing, said spacing providing a passage opening between two neighboring shapes between 3 and 20 times, preferably 7 and 15 times, the average granulometry of said particles, and the vertical projection of the shaped elements completely covering a horizontal section of the column. This packing is very specially recommended in the presence of particles with a granulometry greater than 2 mm or having mediocre flow characteristics.

Abstract: A method of bloating a granular material residing in that a flow of rising gases heated to a temperature of 800.degree.-1000.degree. C. is formed, and a flow of raw granular material is formed to be introduced directly into said flow of rising gases at a velocity 1.5 to 9 times the velocity of rising gases, whereafter said material is roasted to obtain completely or partially bloated granules which are carried by the flow of exit gases away from the zone of roasting. The partially bloated granules of said material are returned to the zone of roasting to roast further until they are completely bloated.

Abstract: A shaft furnace for heat treatment of finely dispersed material has a casing of rectangular cross section with a hopper built into a cover thereof. The top of the casing accommodates pipes for drawing off resultant gases. The casing also houses two groups of plates equidistant from the vertical axis of the casing and having different lengths increasing in the direction from the vertical axis toward a narrow wall of the casing so as to form therebetween and the narrow wall of the casing passages for the flow of gases toward the pipes for exhausting resultant gases.

Abstract: In a shaft furnace for burning limestone or similar raw materials, gaseous, liquid or solid fuels are supplied through fuel supply pipes to the burning zone of a furnace shaft. To permit the simultaneous supply of at least two different fuels, the fuel supply pipes are arranged as multiple fuel lances. The fuel lances extend inwardly from the shaft furnace wall through the preheating zone into the first part of the burning zone. The fuel lance is a double tube member made up of an inner tube laterally enclosed by an outer tube forming an inner fuel supply passageway and an outer annular fuel supply passageway. Two separate fuels can be introduced into the burning zone, one flowing through the inner passageway and the other through the outer annular passageway. The two different fuels can be supplied in varying proportions without any changeover operations.

Abstract: In a double-incline shaft kiln in which ore materials are charged into the furnace from the top of a vertical external portion of the shaft and are calcined by burners installed in the lower portion of the shaft, the calcining zone is effectively extended by the provision of an injector which causes the hot gas to flow in the lower portion of the shaft parallel to the flow of ore materials. Further, at the turnover locations for the ore descending through the shaft, the width of the shaft is broken into at least two portions which promotes a more even velocity of the material flow across the width of the shaft so as to enable combustion control and the prevention of the ash of solid fuel, such as coal, from mixing with the calcined material to cause discoloration and lumps.

Abstract: A method and apparatus for calcining minerals, particularly limestone, in a shaft kiln having at least two vertically spaced levels including cooled hollow supports through which a solid fuel is introduced into the kiln. One feature of the present invention resides in employing a granular coal as the fuel while other features are involved with the distribution of fuel between various inlet points, suspension of the fuel in an airstream, and the mechanical construction of the fuel conduits and their support located within the shaft kiln.

Abstract: A shaft furnace for burning or firing and sintering material, such as limestone, dolomite, etc in lump or pellet form, in which the cooling air is introduced into the external cooling air duct in the vicinity of the furnace bottom, flows upwardly through duct the air duct and downwards through an internal cooling air duct and then passes from an air outlet of internal cooling air duct positioned in the vicinity of the furnace bottom into a first bustle pipe or the like surrounding the shaft furnace. A combustion air duct is supplied with combustion air from a first bustle pipe. A fuel gas supply line runs within the external cooling air duct.

Abstract: A calcining kiln for burning limestone or similar mineral raw material is formed with a wall structure which is gas-permeable at least in a region adjacent the openings of burners extending to the interior of the kiln with a compressed gaseous medium being supplied through the gas-permeable wall structure toward the interior of the kiln.

Abstract: A regenerative shaft furnace for burning carbonate-containing raw materials is disclosed having two or more shafts which are interconnected by ducts which operate in an alternate manner and wherein the burned raw material is cooled in the cooling zone of the shafts. Having a displacer in the cooling zone to prevent the reabsorption of carbon dioxide in the fuel gases by the burned material. A method for burning carbonate-containing raw material is also disclosed.

Abstract: A process and apparatus for manufacturing cement clinker in which pellets of raw material containing the necessary components for manufacturing the clinker are introduced into an apparatus where the pellets flow under gravity, successively through a preheating zone, a clinkering zone using a fluidized bed and a cooling zone. The pellets contain an amount of comminuted carbon determined so that its combustion produces an amount of heat within each pellet sufficient to carry out decarbonation of the material, taking into account the heat introduced by the hot gases passing upwardly through the apparatus. Decarbonation is completed at the base of the preheating zone and the pellets enter the clinkering zone at a temperature which is close to the clinkering temperature. Additional heat is supplied through burners within the clinkering zone.